Dielectric properties of Na1-xLixNbO3 ceramics from powders obtained by chemical synthesis

Ultra-fine powders of Na1-xLixNbO3 (x=0; 0.06; 0.09; 0.12) were synthesized by the Polymeric Precursors Method. Such powders had their orthorhombic st ructures determined by X-ray diffraction and their surface area determined by BET isotherms (less than 10 m(2) g(-1)). Densification was followed by d ilatometric study. The powders, calcined at 700 degrees C for 5 h, were sin tered at 1290 degrees C during 2 h under ambient atmosphere with no applica tion of extra pressure. The samples with relative densities higher than 95% were analyzed by impedance spectroscopy at room temperature, under a signa l amplitude of 1 V-rms. Dielectric constants of about 180 and dielectric lo ss factor of about 0.03 were measured showing small dependence with frequen cy. The electrical properties were similar to those obtained for samples si ntered by hot pressing. (C) 1999 Elsevier Science Limited and Techna S.r.l. All rights reserved.